Regulator for fluid compressors



Oct. 23, 1934. w. RAYMOND REGULATOR FOR FLUID COMPRESSORS v Filed May16, 1952 Patented Oct. 23, 1934 UNITED STATES PATENT 1. OFFICE REGULATORFOR FLUID COMPRESS'ORS Ward Raymond Eas'ton, Pa., assigiior to Pennsylvania Pump 8; Compressor Company, Ea's'ton,

Pa a corporation of Pennsylvania,

Application May 16, 1932, Serial K0. 611,538 6 claims, ,(Cl. 230 44).

to novel means for regulating the unloading and loading of thecompressor in a number of ,dis-' 6 tinct steps so that the volume offluid compressed maybe varied with the demand upon the Compressor andthe discharge pressure kept at sub stantially constant pressure underall loads of the compressor.

In variable volume compressors suchas disclosed in this application, aseries of pressure operated unloading devices are employed, eacheffecting a partial unloading of the compressor, so that the compressorCapacity may be varied in accordance with the operation of the unloadingdevices, these unloading devices being individually operated by aregulator acted upon by the varying pressures within the receiver of thecompressor to move the devices to positions Ior loading and unloadingthe compressor.

'An object of the present invention is to provide a regulator orgovernor mechanism to control the operation of said unloading devices,this mechanism beingcomparatively simple in construction,

positive in'operation, and suchthatsthe receiver pressure may be keptwithin close variations of pressure during wide fluctuations in demandsupon the compressor.

More specifically, the present invention com-' priseslaplurality ofindividually operating distributing valves for controlling thedistribution of fluid under pressure to the individually oper atedunloading devices each unloading device serving to partially unload-thecompressor, these cessively actuate the individual distributor valves;40 in their proper order. i

And finally it is an object to employ'mercury switches oscillated toopened and closed positions by movement of a regulator actuated byvariations in receiver pressure, these switches when closed servingindividually to energize electro magnets and when open energizing otherelectromagnets respectively controlling fluid valves for theadmission-and withdrawal of fluid underpres sure to and from thedifferent unloader devices.

invention, includes the features of construction and operation set forthin the followin specifi cationiand illustrated in the accompanyingdrawing. :1; a

With the above and other objects in view my In theaccompanyingdrawingannexed hereto;

and forming a part of this specification I have shown my inventionembodied in a single cylinder air compressor; but it will be understoodthat the inventioncan be otherwise embodied and that the drawing is notto be construed as defining or limiting the scope of the invention, theclaims appended to this specification being relied upon for thatpurpose,

vIn the drawing;

Figure 1 is a front elevation or the control m chanism showin t econnections to a comp essor cylinder,

Fig, 2 is a side elevation of a portion of the controller mechanism,

i 3 is n nla g d'view of one of the elec- 7o troma netlcally operatedvalves for controlling the supply of fluid to the unloader devices, and

F -A is an enlarged view of one of the mercury switches. H

In the above mentioned drawing I have shown 15 but one embodiment of theinvention which is now deemed preferable, but it is to be understoodthat c an s and m difi a ns may be m d within-the scope of the appendedclaims without-departin .fromthe spirit of th invent on- Briefiy and inits broadest aspect my invention may includ the io lowing princ pal pars: F r a compressor cylinder havin a'plurality of unloading meansoperated by variations in discharge pr s eac a t n to partially un adthecYI- s5 denseco d, d v dua va es co troll ng ad missio and exhaust orf u d to a d iro said unloading means; t i d, s tromagn 09 r v v onne dto sai va ves for actu in sa d valves; fourth, switches individuallycontrolling the energizing of said magnets; and mm, pressure responsivemeans operating at slightly vary.- ing pressures to actuate saidswitches, v I

Referring more particularly to the figures of the drawing, anaircompressor cylinder is shown at 10' in which the pistonllreciprocates in the usual manner for compressing the fluid. In thecylinder 10fthe unloading and loading is accomplished by four individualunloading means 12 operating respectively upon four valves 13 (one'onlyfbeing shown) controlling admission of fluid being compressedtoreceivers or clearance pock ets'li, It is to be understood, however,that the present unloading or controlling means illus- I trated anddescribed in this specificationmay be employed with any form ofcompressors employingother methods, offunloading. v

. The control or governing apparatus for the unloading means 12 embodiesa pressure actuated lever 15. "lhislever .15 is pivotally supported atan intermediate point, one end of the lever engaging a member 16attached to the center of a pressure diaphragm 17. The opposite end ofthe lever 15 is suitably weighted by weights 18 suspended as willpresently be described. Actuated by oscillation of the lever 15 is avertically movable rod 19 on which are mounted spaced collars 20.Preferably the lever 15 has attached to it a depending arm 21 the lowerend of which is attached to a bar 22 into which the lower end of rod 19is fastened.

By reference to Fig. 1 it will be seen that the lever 15 moves fromslightly'below horizontal position to slightly above horizontal. Thelink23 connected to the weights 18 moves from one oblique position toanother below the horizontal. These oblique positions are of greaterangle than the positions of the lever 15. It follows, therefore, that asthe lever rises by increased pressures above the diaphragm 17 theWeights 18 move slightly outwardly along thelever 15. The pressurerequired to raise the lever to successively higher positions increasesslightly by reason of the slightly increased arm at which the weights 18act upon the lever 15. To the enclosed space above the diaphragm 1'7fluid under pressure may be admitted directly from the compressorreceiver (not shown). For this purpose a connection 24 is provided. Theoscillated position of the lever 15 therefore varies with variations ofthe discharge pressure of the compressor.

Adjacent the collars on the vertically disposed rod 19 are electricswitches 25, those shown being of the mercoid type. These switches 25 Iinclude a tiltable tube 26- containing a small amount of mercury whichin one oscillated position of the tube 26 covers the terminals of cables27 entering the tube. In the other oscillated position these terminalsare above the level of the 'mercury. By oscillating this tube 26therefore switches 25 are successively operated by continuous upwardmovement of the vertical rod 19 as the collars 20 are at successivelygreater distances from the different arms 28. As the rod 19 starts itsmovement upward the lowermost switch 25 first is actuated and then thesecond and so on for as many switches as may be provided. To retain thetube 26 of a switch 25 resiliently in either of its oscillated positionsa spring 29 may be mounted on the member 30 carrying the arm 28. Theresilience of spring 29 retains the member 30 in oneof its positions butpermits movement of the tube 26 by slight pressure against the arm 28.The tube 26 may be pivoted at 31 to the frame of the switch andconnected to the member 30 by a short connecting arm 32. As

' these mercoid switches arewellrknown and form have fluid underpressure admitted, to them through individual valves- 35. Each of thesevalves 35 is electromagnetic'ally operated by the coil 36 associatedtherewith and which may be energizedby their respective switches 25being tilted to one oscillated position. With a valve 35 open fluid isadmitted to the outer end of a device 12 which forces a piston in adirection to force a valve 13 to an open position. This latter Valve 13of which there may be one for each switch 25 and electromagnetic valve35 admits a portion of the fluid being compressed to a clearance pocket14'thus fractionally unloading the cylinder as is well-known.

The structure of valve 35 is indicated in Fig. 3. A solenoid 37 withinthe coil 36 has a needle or conical valve 38 at its lower end. With thecoil 36 energized=the armature is forced upwardly to move valve 38 fromits seat 39. Fluid may therefore be admitted from connection 40 suppliedwith receiver pressure to the connection 41 leading to one of theunloader devices 12.

;With coil 36 deenergized the armature 37 rests with its entire weightupon the seat 39 so that valve 38is effectively closed. Fluid thereforeis prevented from entering connection 41 and the unloader device 12 isnot operated.

To release the pressure from the connections 41 to render the unloaderdevices 12 inoperative a second series of valves 42 is provided. Thesevalves 42 are in every way similar to valves 35 but are connected asshown in Fig. 2 in a manner opposite to valves 35. Fluid enters valves42 from connection 41 through a branch 43 therein and may be admitted toatmosphere from the connection 44.

Each unloader device 12 has its individual connection 41, valves 35 and42 and switch 25. The first upward movement of lever 15 operates ondevice 12 through one ofthe switches 25 and valves 35 and 42. Continuedupward movement of lever 15 operates another unloader device 12 throughthe second switch 25 and so on. With a slight drop in receiver pressureand consequent lowering movement of the lever 15 a collar 20.moves awayfrom an arm 28 permitting a switch. 25 to return to open position thusde-en ergizing the coil 36 of valve 35. This allows valve 35 to close.Simultaneously the valve 42 is opened so that pressure mayexhaust fromthe connection 41.

. The coils for the valves 35 and 42 are wired in a circuit so that whenone coil is energized the other is-de-energized. With the switch in theposition shown in Fig. 4 the coil 36 for valve 35 is de-energized, whilethe coil for valve 42 is en-' ergized thus opening valve 42. In thisposition of the valves 35 and 42 no pressure can build up in theconnection 41 so that the unloader device 12 for that set of valves isin position for normal energized at a time, and a bar having anundulating surface and moved upon variances in pressure of fluidcompressed for operating said switches.

2. In a variable volume compressor, the combination with a cylinder, ofa plurality of pressure-operated unloading devices, each acting topartly unload the cylinder, a distributing valve for supplyingpressurefluid to each of said unloading devices, exhaust valves for said devicesindependent electric operating means associated with each of saidvalves, whereby but one valve for an unloader device is open at a timeand a bar having an undulating surface and moved upon variances inpressure of fluid pumped for operating said electrical operating means.

3. In a variable volume compressor, the combination with a cylinder of aplurality of pressure operated unloading devices each acting to partlyunload the cylinder, a distributor valve for supplying pressure fluid toeach of said unloading devices, exhaust valves for said devicesindependent electric operating means associated with each of saidvalves, whereby but one valve for an unloader device is open at a time,and a rod having a series of projections thereon movable upon variancesin pressure of fluid pumped for controlling energizing of saidelectrical means.

4. In a variable volume compressor, the combination with a cylinder, ofa plurality of pressure operated unloading devices each acting to partlyunload the cylinder, a distributing valve for supplying pressure air toeach of said unloading devices, independent electric operating meansassociated with each of said valves, whereby but one valve for anunloader device is open at a time, a rod having a series of projectionsthereon movable upon variances in pressure of fluid pumped forsuccessively controlling energizing of said electrical means, and acompensator structure associated with said last named means forautomatically adjusting it to increase or decrease the pressuresrequired for operating said means. I

5. The combination with a variable volume air or gas compressor, ofpressure operated unloading devices for loading and unloading thecompressor, admission and exhaust valves of the needle type forcontrolling admission and exhausting of pressure fluid to and from saidunloading devices, a solenoid connected to each of said distributorvalves for operating them, switches for controlling energizing of saidsolenoids, and a bar having spaced enlargements thereon moved axiallyupon variations in discharge pressure of the compressor, said switchesbeing disposed adjacent said projections for successive operationthereby.

6. The combination with a variable volume air or gas compressor, ofpressure operated unloading devices for loading and unloading thecompressor, distributor valves for controlling admission of pressurefluid to said unloading devices, a solenoid connected to each of saiddistributor valves for operating them a solenoid controlled exhaustvalve for each of said unloading devices, switches for controllingenergizing of said solenoids, and a vertically disposed bar movedaxially upon variations in discharge pressure of the compressor, saidbar having spaced projections thereon and said switches having operatingarms extending into the path of and actuated by said projections wherebysaid switches may be successively operated by movement of said rod inone direction.

WARD RAYMOND.

